Sheet grade polycarbonate (aka Lexan or Makrolon) and acrylic sheet (aka Lucite) are two of the most frequently used see-through plastics.
Each of the two have benefits and drawbacks. Acrylic is shinier and polycarb is stronger. Acrylic is less expensive but easier to crack. Polycarb is more impact resisant but easier to scratch. They are both stronger and lighter than untempered glass; acrylic is 4x to 8x stronger than glass, while polycarb is about 200x stronger.
A video produced by the motorcycle windshield company National Cycle illustrates some of these differences by showing the effect of various projectiles and weapons on both acrylic and polycarb windshields.
By the time you finish watching a faceless guy in the video hit the windshields with everything from a slingshot to a baseball bat (and a hammer, shotgun and semi-automatic pistol) you'll get the idea that polycarb bends (and scratches) but doesn't break; and that acrylic stays stiff and shiny but cracks and shatters under impact.
Another way to show the differences is to list some of the common uses for each of these two materials.
Common Uses for Acrylic Sheet:
- Fish tanks and aquariums
- Animal and reptile enclosures
- Retail product displays
- Storm window linings (interior layer)
- Hockey rink glass
Popular Uses for Polycarbonate (Lexan):
- Race car windows
- Transparent visors for hockey and football players
- Window well covers
- Re-usable drinking bottles
- Computers: Apple, Inc.’s MacBook, iMac, and Mac mini
- Machine guarding glass
- Laminated layers of polycarbonate can be engineered to stop various size bullets
We've got the remnant bins ready again, because this Friday, March 22, 2013, from 8am to 5pm, is our next one-day, Fourth Friday of the Month Half-Price Remnants Sale!
Please Join us at our One and Only Louisville location as we Once Again offer you, our Customers, an Opportunity to Obtain Enormous Value on Engineering, Machinable and See-Through Plastic Remnants of sheet, rod and tube..
- We will be open our normal hours of 8am to 5pm.
- No Minimum Purchase Amount is Required for this Sale.
- Fax and e-mail requests will not be accepted this month. We will also be unable to ship your puchase half-price remnants this month.
Please join us at our one and only Louisville location as we Once Again offer You our Customers, an Opportunity to Obtain Enormous Value on Engineering, Machinable and See-Through Plastic Remnants of sheet, rod and tube..
Colorado Plastic Products is located at 500 S. Arthur Ave, Louisville, CO 80027 (see map below or click here to open it in a new window):
Our regular business hours are M-F, 8am -5pm.
Plastic: The Making of a Synthetic Century was written by Stephen Fenichell in 1996 as a history of the plastics business. It describes the winding path that a wide range of plastics took from the lab to the marketplace. The book is filled with many, many interesting anecdotes about the entrepreneurs who blazed that trail.
The book is organized into 13 chapters arranged, mostly, in chronological order. There is the predictable, "Just one word......Plastics" cliche from The Graduate movie used as a preface. The book begins with a late 20th century scene setting chapter. Mr. Fenichell then rolls the clock back 150 years to explain the commercialization of rubber, which he properly calls "Nature's Plastic".
There are chapters about celluloid, Bakelite, and cellophane with historical vignettes about their respective titans named Eastman, Baekeland and Brandenberger. There is a dramatic account of the tragic life of Wallace Hume Carothers, the inventor of nylon. But my favorite chapter is the one entitled, "Plast-O-Rama" which highlights the ways in which post-war America went bonkers for all things plastic. From Silly Putty and Hula Hoops to Frisbees and Tupperware and Saran Wrap, it's all in this book.
Overall it thought that the Pro's of this book were:
- It's a good historical overview of plastic
- It's loaded with facts about plastic
And I thought the only Con of this book was:
- The history is presented out of chronological order for no apparent reason
This book will be of interest to:
- 20th century pop historians
- polymer chemists
- plastic trivia buffs
- anyone who makes their living selling or producing plastic
- employees or former employees of Dupont, Rohm & Haas, Eastman Kodak, Ford Motor Company and General Electric
- industrial designers
- material science students
- manufacturing entrepreneurs
ABS (Acrylonitrile-Butadiene-Styrene) has a is a common plastic composed of three separate monomers from which it takes its name. It is a copolymer which is formed when styrene and acrylonitrile are polymerized in the presence of a third material called polybutadiene.
ABS is a thermoplastic that that is hard, rigid and tough, even at low temperatures. ABS is readily thermoformable and it can be easily bonded with solvent based adhesives.
Flat sheets or plates of ABS come in two different forms called sheet grade ABS and machine grade ABS.
People sometimes ask us, "what is the difference between sheet grade ABS and machine grade ABS"?
The three biggest differences between the two forms of ABS are:
- Sheet grade ABS is extruded and not heat treated so it is unsuitable for most close tolerance machined parts. Machine grade ABS is compression molded, or extruded, and then annealed via gradual heating and cooling to minimize internal stresses that are hugely problematic for machining.
- Sheet grade ABS is normally available up to 3/8" in thickness only. Machine grade ABS is normally available only down to about 1/4" or 3/8" in thickness.
- Machine grade ABS is priced roughly twice as high as sheet grade ABS.
||Sheet Side Textures
||White and Black
||Natural (Ivory/Butterscoth) and Black
||Retail Price $/lb
For datasheets on sheet grade ABS and on machine grade ABS:
Polycarbonate (Lexan, Makrolon, Tecanat, Zelux, etc.) is a very durable material. The characteristics of polycarbonate are similar to those of polymethyl methacrylate (aka PMMA, acrylic, Lucite, etc.), but polycarbonate is stronger, usable in a wider temperature range and more expensive.
Dr. Hermann Schnell of Bayer in Germany invented the polycarbonate resin in 1953, just one week before chemist Dr. Daniel Fox of GE independently made the same discovery while working on a wire coating. They had created a gooey substance that once hardened, could not be broken or destroyed without great effort. Both teams were impressed by the remarkable toughness of the material.
Both companies applied for U.S. patents in 1955. Before it was clear which would win the patent, both agreed that the patent holder would grant a license for an appropriate royalty.This agreement allowed both companies to concentrate on developing the polymer and was particularly advantageous to GE, since GE would not otherwise have been able to sell a product during the life of the original patent.
Flat sheets or plates of polycarbonate come in two different forms called sheet grade polycarbonate and machine grade polycarbonate.
People sometimes ask us, "what is the difference between sheet grade and machine grade polycarbonate"?
The four biggest differences between the two forms of polycarbonate are:
- Sheet grade is extruded and not heat treated so it is unsuitable for most close tolerance machined parts. Machine grade is compression molded, or extruded, and then annealed via gradual heating and cooling to minimize internal stresses that are hugely problematic for machining.
- Sheet grade is readily available in window-clear sheet. Machine grade is not.
- Sheet grade is normally available up to 1/2" in thickness only. Machine grade is normally available only down to about 1/4" or 3/8" in thickness.
- Sheet grade is priced roughly 30% higher than sheet acrylic (aka PMMA and Lucite). Machine grade polycarbonate is priced roughly three to four times as high as sheet grade.
||No, except Zelux W
||Clear, White, Black, Bronze, Gray
||Natural and Black
|Retail Price $/lb
People sometimes ask us, "What is the difference between Delrin and acetal"?
Both names refer to a class of polymers known as polyoxymethylene or (POM), POM is also known as acetal, polyacetal and polyformaldehyde which are forms of an engineering thermoplastic used in precision parts that require high stiffness, low friction and excellent dimensional stability. Examples of parts that are frequently machined from the acetal plastics, incuding Delrin, are wear strips, rollers, and bushings and other applications requiring a combination of strength, low moisture absorbtion, dimensional stability and chemical resistance.
Delrin is DuPont’s trade name for acetal homopolymer. Acetal is the name generally used in the plastics industry to refer to acetal copolymer.
Homopolymers are polymers that contain only a single type of subunit in their chain and copolymers are polymers containing a mixture of more than one type of subunit in their chain.
They each have their advantages and disadvantages.
At Colorado Plastics we generally recommend acetal (acetal copolymer) for plate shape applications and Delrin (acetal homopolymer) for rod shape applications.
Advantages of Delrin:
- Higher Crystallinity = somewhat better mechanical properties includind tensile strength, resistance to creep and impact strength
Advantages of Acetal:
- No centerline porosity
- Better property retention at elevated temperatures
- Frequently has lower resin and stock shape price
- Available as FDA compliant n both black and natural = white colors
- Better chemical resistance to fuels and solvents
Disadvantages of Delrin:
- Smaller number of resin producers can lead to higher prices, although at Colorado Plastics we can typically offer both Delrin and acetal at the same price
- Centerline porosity = midline cavitation at centerline of plate depth or crystalline dot at center of rod diameter
Disadvantages of Acetal:
- Lower crystallinity = somewhat lesser mechanical properties (although some data shows this difference goes away over 12 - 24 months of age of plastic parts)
For datasheets on Ensinger brand Delrin and acetal sheet, plate and solid round mechanical plastic rod:
Here's a short animated video I came across recently:
It explains ways that plastic can lead an interesting life in providing break resistance and reducing weight; which can lead to savings of money and energy. It is narrated by someone named Ellie who seems to know a lot about plastic and how it can be used to reuse, recycle and recover.
SparkFun, of Boulder, Colorado, is an online retail store that caters to the Maker Movement and sells the bits and pieces to make your electronics projects possible. Whether it’s a robot that can cook your breakfast or a GPS cat tracking device, their products and resources are designed to make the world of electronics more accessible to the average person. In addition to products, SparkFun also offers classes and a number of online tutorials designed to help educate individuals in the wonderful world of embedded electronics.
Sparkfun products range from things like resistors and LEDs to humidity sensors and LCD screens. Their goal is to make finding the parts and information the makers need easier and affordable so you can create awesome projects.
Sparkfun customers include crafters and designers, artists and DJs, elementary teachers and college professors, prototype makers and electrical engineers. They have seen 5-year olds soldering their kits and octogenarians attending their events. Sparkfun believes anyone and everyone can play with cool electronic gadgets.
In a recent post to their website, Sparkfun described a team shopping trip to Colorado Plastics. Since they needed well over 30 square feet of acrylic plastic sheets, they loaded up the Sparkfun Van and headed over to our facility in Louisville, CO. We were able to set them up with a number of Plexiglas plastic pieces, in a variety of colors that that cut up for robot parts on their Epilog laser in their shop. The final result was a multi-colored Battle Floor arena, with a trapdoor that can be shifted around the floor, for their fighting robots.
As a plastic distributor, I like to read books about the history of plastics. As a Colorado resident, and husband to a professional conservationist, I enjoy learning more about environmental issues. I got a chance to do both when I when I recently read the new book, Plastic; A Toxic Love Story by Susan Freinkel.
The author decided to spend a day without touching anything plastic. But she didn't make it too far. About 10 seconds, she estimates...since both the light switch and the toilet seat in the bathroom were made of plastic. So she changed the experiment into a list-making exercise and that day she wrote down 196 different plastic items that she touched. Of course, many of these items were non-durable items like plastic packaging. The next day she continued list-making with a similar tally of everything she touched that wasn't at least partially made of plastic. The non-plastic list only made it to 102 items.
This led to some reflection and a list of questions, which she attempts to answer in the book. Those questions include:
- What is plastic?
- Where does plastic come from?
- How did we get so many plastic items in our lives without really trying?
- What happens to plastics after we put them into a recycling bin?
- Does plastic actually get recycled after it's picked up curbside?
- How much of the plastic that the typical American discards is ending up in the ocean?
- Should we stop using plastic shopping bags?
- Is there a future for plastic in a sustainable world?
To explore the answers to these questions, the book is organized into separate chapters about eight common, everyday, relatively non-durable objects that are commonly made from plastic, including the comb, the stackable cafe chair, the Frisbee, the intravenous solution bag, the disposable lighter, the grocery bag, the soda pop bottle and the credit card.
Two of my favorite factoids in the book were:
- In the 19th century plastics were actively promoted as a way to replace ivory from elephant tusks for use in billard balls and to replace hair comb materials that were coming from hawksbill turtle shells.
- The rapid growth of plastics after World War II had a lot to do with their utility as a way to use the ever-increasing stream of petroleum refining by-products.
Overall it thought that the Pro's of this book were:
- It's a good historical overview of plastic
- The author acknowledges the paradoxes of the plastic industry
- There is a good chapter explaining what the recycling numbers on plastic products indicate and where they came from
- And there's an excellent notes section at the back of the book
And I thought the Con's of this book were:
- No durable plastic items were examined
- No full-scale solutions for the paradoxes of our huge reliance on non-durable plastic products were identified or examined
Colorado Plastic Products was hired by the Early Television Museum of Hilliard, OH, to construct a clear plastic replica of the case for a Lucite TRK-12 television set; just like the one that was on display at the 1939 Worlds Fair.
The Early Television Museum lent us an original wood case, the electronic guts from another TRK-12 and some photos of a another replica case to work from. Over many hours of fabrication, John Butler was able to create a museum grade case for exhibit in Australia. One inch thick clear acrylic sheet was bonded using IPS Weld-on adhesive compounds including Weld-on #3. And since the picture tube is mounted vertically in the RCA TRK-12 (which means the image is viewed on a mirror in the lid), a hinged clear acrylic lid needed to be part of the project. And since the outside of original wooden case was wrapped with eight ribs, the replica case needed to have the same number of clear plastic ribs heat bent to match the outside profile of the case.
The final version of the TRK-12, on display in its exhibit, looks like this: